1. Field of the Invention
The present invention relates to an endoscope insertion shape observation apparatus, and more particularly, to an endoscope insertion shape observation apparatus configured to observe an insertion state of an endoscope.
2. Description of the Related Art
Conventionally, endoscopes for medical use are widely used which insert an elongated insertion portion into a bent body cavity to observe organs or the like in deep parts in the body cavity without dissecting the body surface or which use, if necessary, a treatment instrument inserted into a treatment instrument channel of an endoscope insertion portion, to realize various types of therapy or treatment or the like.
Since a lumen such as a large intestine or a small intestine in a body cavity which is a subject is bent, making it clear up to which position of the lumen, the endoscope insertion portion is inserted or what shape the endoscope insertion portion takes may improve operability of observation or treatment using the endoscope.
Thus, for example, Japanese Patent Application Laid-Open Publication No. 2005-305047 discloses an endoscope insertion shape observation apparatus configured to incorporate a shape detection coil in the endoscope insertion portion, detect the position of the shape detection coil by receiving an electromagnetic field signal generated by the shape detection coil and display the shape of the endoscope insertion portion on a monitor or the like.
Regarding the insertion of a large intestine endoscope into the large intestine which includes many complicated bent conduits, since the shape of the intestine is extremely varied from one person to another, the insertion of the large intestine endoscope involves difficult manipulation and mastering such manipulation takes considerable effort. For that reason, a method is adopted which uses an endoscope insertion shape observation apparatus as disclosed in Japanese Patent Application Laid-Open Publication No. 2005-305047 as auxiliary insertion means, determines a bending angle while watching the endoscope insertion shape and assuming the luminal direction from the endoscope position, takes advantage of varying rigidity depending on how the endoscope advances and inserts the endoscope into deep parts.